<template>
    <div v-if="!item.hidden" class="menu-wrapper">
        <!-- 仅有一个可显示的子路由，并且该子路由没有子路由 -->        
        <template v-if="hasOneShowingChild(item.children, item) && (!onlyOneChild.children || onlyOneChild.noShowingChildren) && !item.alwaysShow">
            <router-link v-if="onlyOneChild.meta" :to="resolvePath(onlyOneChild.path)">
                <el-menu-item :index="resolvePath(onlyOneChild.path)" :class="{ 'submenu-title-noDropdown': !isNest }">
                    <item :icon="onlyOneChild.meta.icon||(item.meta && item.meta.icon)"
                        :title="onlyOneChild.meta.title" />
                </el-menu-item>
            </router-link>
        </template>
        <el-submenu v-else ref="subMenu" :index="resolvePath(item.path)" popper-append-to-body>
            <template v-slot:title>
                <item v-if="item.meta" :icon="item.meta && item.meta.icon" :title="item.meta.title" />
            </template>
            <sidebar-item v-for="child in item.children" :key="child.path" :is-nest="true" :item="child"
                :base-path="resolvePath(child.path)" class="nest-menu" />
        </el-submenu>
    </div>
</template>

<script>
import Item from "./Item.vue"
// import path from "path"
import path from 'path-browserify';
export default {
    name: "SidebarItem",
    components: {
        Item
    },
    props: {
        // route object
        item: {
            type: Object,
            required: true
        },
        isNest: {
            type: Boolean,
            default: false
        },
        basePath: {
            type: String,
            default: ""
        }
    },
    data() {
        this.onlyOneChild = null
        return {}
    },
    methods: {
        hasOneShowingChild(children = [], parent) {
            const showingChildren = children.filter(item => {
                if (item.hidden) {
                    return false
                } else {
                    // Temp set(will be used if only has one showing child) 如果只有一个子菜单，则将其设置为onlyOneChild
                    this.onlyOneChild = item
                    return true
                }
            })
            //当只有一个子路由时，默认显示子路由
            if (showingChildren.length === 1) {
                return true
            }
            //如果没有子路由，则显示父路由
            if (showingChildren.length === 0) {
                this.onlyOneChild = { ... parent, path: "", noShowingChildren: true }
                return true
            }
            return false
        },
        
        resolvePath(routePath) {

            return path.resolve(this.basePath, routePath)
        }
    }
}

</script>